Get Air Music Tech OPx-4 FM Synthesizer For $29.99


ADSR Sounds launched a $29.99 deal on OPx-4 ($149 value), a virtual FM synthesizer by Air Music Tech.

OPx-4 is a powerhouse FM plugin. It offers four operator FM synthesis engine and a myriad of sound design possibilities.

The instrument has all the features you’d expect from an advanced FM synth, like wave looping, sample offset, multiple filters, morphing, filter movement, and more.

It also has built-in effects such as compression, EQ, delay, reverb, and lo-fi. And to top it off, OPx-4 has eight assignable macro knobs plus a 32-slot FM modulation matrix. So you can get deep, nuanced sounds no matter your skill level.

OPx-4 sports an intuitive control layout to help beginners make their first steps with FM synthesis.

On the other hand, its highly detailed sound editing capabilities make it a joy to use for advanced synthesists. Air Music Tech’s powerful FM synth lets you sculpt, morph, and shape your sound with remarkable precision.

The instrument includes multiple preset banks that provide easy access to classic and modern FM sounds. So if you’re looking for legendary FM electric piano (EP) sounds, 80s FM synth sounds, or unique sound effects, you’ll find what you need in OPx-4.

What makes the OPx-4 a must-have right now is the low price that ADSR Sounds offers. For only $29.99, you can access a groundbreaking synthesizer with advanced FM sound manipulation capabilities.

It’s also worth noting that OPx-4’s sounds can be accessed in Akai MPC/FORCE units. So, if you’re a proud owner of AKAI’s sample mangling hardware, here’s a great way to expand its sonic arsenal.

For those in the market for a powerful and versatile instrument, the OPx-4 by Air Music Tech is a good opportunity. With an unbeatable price of only $29.99 and access to exclusive resources, you’ll be well on your way to crafting stunning soundscapes in no time.

OPx-4 is available in 64-bit VST2, VST3, AU, and AAX plugin formats for digital audio workstations on Windows and macOS.

Take advantage of this sale at ADSRSounds and add a versatile FM sizer to your music production toolset.

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Get the deal: OPx-4 ($29.99 for a limited time)


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About Author

Tomislav is a music producer and sound designer from Belgrade, Serbia. He is also the founder and editor-in-chief at Bedroom Producers Blog.


  1. Since it is Air Music, it is prolly out dated and on sale because they are trying to dump it before they fix all of the issues and resell it as an upgrade. Toontrack does thus too, orolly all of them do this.
    Usually show up in the GUI, which do not have interface scaling and wind up too small for modern systems.
    My Air Loom2 has an interface that becomes mangled in some daws.

    • Unfortunately, This is true. I still use vacuum pro and xpand2 and they’re so outdated but I just love them especially xpand2. It’s so second nature to me and I can literally find everything I need in it…But the plugins have serious GUI issues. In reaper(my main daw), vacuum pro GUI stops working sometimes and I need to restart reaper. Also, Both of them are only available in vst2

  2. Similar issues here with Hybrid 3.
    It needs a pesky iLok, which keeps unauthorizing itself whenever the mood takes it, and the amount of hoops I have to jump through just to get the damn thing working just makes it not worth the hassle.
    I also need an electron microscope to see the interface, and I haven’t even got a 4/8k monitor.
    I’ll stick with Surge XT:)

  3. Ruud van Roijen


    When i look on the website from ADSR the OPx-4 FM Synthesizer in Euro’s are € 167,- Is the ammount from $29.99 only for US custimers?

  4. This product did not work on a 64bit windows 7 system. I have filed a support ticket with the makers… I get an error saying a certain kernel.32 file can’t be found. Works great on my windows 10 system.

  5. Yeah, I have to stop with Air plugins and recommend others to avoid the company.

    They don’t update the plugins I have bought (for example Structure sampler as well as Ignite). They make new versions of plugins with different numbers (version 2, 3 etc) which destroys backward compatibility, meaning you can not open your old sessions and songs.

    IK Multimedia and Arturia also use this bad practice of abandon plugins and make other versions (2, 3, 4 etc).


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